Dropper assembly



Jan.27,1959v P AgMRCHANT 2,870,797

DROPPER ASSEMBLY Filed April l5. 195'? United States Patent O DROPPER ASSEMBLY Paul A. Merchant, Kansas City, Mo., assignor to Injection Molding Company, Kansas City, Mo., a corporation of Missouri Application April 15, 1957, Serial No. 652,847 s claims. (ci. 141-24) This invention relates to droppers for 'liquid containers and refers more particularly to a dropper engaged with the cap of a container which is sealed when the cap is screwed on the container or otherwise fixed thereon.

This application is an improvement over my application Serial No. 613,266, tiled October l, 1956 and entitled, Dropper Assembly.

An object of the invention is to provide a container cap dropper assembly comprising a pipette, a resilient squeeze bulb and a container cap with which the bulb and pipette are engaged wherein the bulb and container are both sealed when the cap is screwed on or otherwise fixed to the top of the container.

Another object of the invention is to provide ksuch a three-component liquid container cap dropper assembly of an exceedingly simple construction which permits the molding of all the parts from'suitable materials, including resilient materials for the bulb and dropper pipette if desired, and which is easily and swiftly assemblable.

Another object of the invention is to provide ysuch a three-component cap dropper assembly which has an extremely durable construction making possible va long life of use therefor despite heavy and continued use.

Another object of the invention is to provide such a three-component liquid container cap dropper assembly which will permit the construction of all parts of the assembly of materials which will not deteriorate under the chemical actions of varied container contents, the use of these materials yet not sacrificing lthe sealing and other functional advantages provided by ythe unique vconstruction.

Another object of the invention is to provide a threecomponent cap dropper assembly Vwherein `the bulb of the assembly is inserted in a hole in the cap and seals to the walls thereof both inside and outside of the cap by its own resilience and rigidity, the pipette then sealing to the inside of the bulb and aiding in maintaining the bulb in sealing relationship with the cap by the pipettes additional resilience and rigidity.

Another object of the invention is to provide such a cap dropper assembly having three components wherein the components are easily and quickly assembled without damage to any of the components but yet wherein the separation lof the components from one another after assembly is exceedingly difcult, thus vproviding a strong, unitary assemblage. v

Another object of the invention 4is to provide a liquid container cap dropper assembly which can be employed to hold a sealed charge within the cap dropper assembly relative the container liquids indefinitely for mixture with the container contents when the container is openedA for use, this feature provided by the unique interengaging sealing structure of the pipette, bulb'and container cap comprising the assembly.

It should be pointed out relative the above listed apassembly, that this original assembly, while producing ,p 2,870,797 Patented Jan. 27., 1959 an air tight dropper, had a number of disadvantages. In the rst place, the frictional engagement between the pipette and the bulb was not as great as desired and the efciency of the interlocking engagement of the bulb with the pipette was not as strong as desired. Thus, the assembly was too easily pulled apart as well as relatively diliicult to assemble. previous modication, there was a ange on the pipette which lay against the undersurface of the cap which was contacted by the upper rim of the bottom when the container top was screwed thereon. The bulb, on the other ice hand, frictionally engaged a hole in the cap top. Thus when the cap top was screwed 'on the bottle, the bulb would be carried with the top while the pipette very often would rotate with the bottle. Thus, the parts might turn one within the other, which was undesirable, especially when there was a sealed charge within the bulb. This difficulty arose out of opposing forces being exerted on the two parts.

Therefore, an object of the present invention is to provide a three-component cap dropper assembly wherein a bulb and a pipette engage one `another within a cap top, a maximum of bearing surface being provided between the bulb and pipette to maximize the force required to separate these parts.

Another object of the invention is to provide such a three-component rdropper assembly wherein engaging means are provided between the pipette and the bulb. the engaging means being positioned so as to maximize its efficiency.

Yet another object of the invention is to provide such a three-component dropper assembly wherein, when the container top is being screwed on the container or otherwise fixed thereto, no opposing forces are exerted on the various parts of the assembly and thus there is no tendency for the parts to turn one within the other.

Other and further objects of the invention will appear v in the course of the following description thereof.

In the drawings, which form a part of the instant specification and are to be read in conjunction therewith, an embodiment of the invention is shown and, in the various views, like numerals are'employed to indicate like parts.

Fig. 1 is an exploded cross-sectional view showing the three parts of the dropper assembly disassembled and spaced relative one another prior to assembly, all of the parts being shown sectionally.

Fig. 2 is a side view with parts cut away and in section to illustrate the interengagement of the three parts of the assembly shown separately in Fig. 1, when assembled.

Referring to the drawings, and more particularly to Fig. l, at f6 is shown the squeeze bulb for the inventive dropper assembly.. It should be noted here that the squeeze bulb and pipette are preferably made of a somewhat resilient, yet, dimensionally stable material, such as polyethylene, as it is necessary that not only the squeeze bulb is squeezable but the lower end of the squeeze bulb and the upper end of the pipette be vconipress'ible vwith a tendency to return to their original form before compression. The cap top itself should be essentially rigid and stronger than the bulb and pipette so as to compress them without motion or distortion of itself.

The bulb has upper closed end lita and lower open end 1Gb. The lower portion of the bulb is preferably formed to a greater outside diameter than the cuter diameter of the bulb thereabove as shown at c. The portion 10c is kpreferably also thickened in cross section somewhat as compared to the upper portion of the bulb to give it greater rigidity while still maintaining va 'certain amount of resilience. A radial flange 10d extends out? In the second place, in this wardly from the lower portion of the thickened portion c of the bulb. Engaging means or a groove 10e is is formed on the inner surface of the bulb thickened portion 10c and intermediate the upper and lower ends thereof. The thickness` of the thickened portion 10c preferably tapers or is less going toward the lower end of the bulb.

Cap 11 has opening lla in the top 11b thereof and also has depending container engaging flange llc extending downwardly from the outer edges of the top 11b with threads 11d formed therein. 'A flange receiving recess 11e is formed on the underside of the top circumferential to the opening 11a.

The outer diameter of the upper portion of the bulb is preferably slightly less or not greater than equal to the inner diameter of the cap opening lla so that the upper portion of the bulb may be forced easily up through said opening. The outer diameter of the enlarged portion 10c is preferably slightly greater than the inner diameter of the opening 11a so that when the resilient bulb is forced into the cap top so the flange lild lies in the ilange recess 11e the portion lila of the bulb will be under compression and thus in strong frictional contact with the boundary of the opening lla. The thickness of the flange 10d is preferably slightly greater than the depth of the an'ge recess lle so that when the container is screwed into the top the top of the container will ram the ange 10d upwardly against the upper surface of the recess to seal the flange against the cap top. As the portion 10c is of greater outer diameter upwardly and slightly thicker upwardly, the portion thereabove which lies above the top of the opening tends to bulge outwardly as in Fig. 2 and lock the bulb in the cap top and seal the top of the opening. The outer diameter of the flange 16d is slightly less than the inner diameter of the flange recess 11e.

At 12 is shown the pipette. Pipette l2 has an open lower end 12a, preferably relatively thick walled and rigid adjacent this end and an open upper end lZb. The body of the pipette, 12C, is preferably relatively thin walled and relatively resilient although dimensionally stable. The upper open end of the pipette is preferably formed to an outer diameter slightly greater than the inner diameter ofthe bulb portion 10c. exerted to force the pipette upper end into the bulb lower end. The pipette upper end 12d is preferably thickened for greater rigidity as shown in Fig. l. The outer surface of the portion 12d is preferably tapered to correspond with the taper in the bulb portion tlc on the inner surface thereof. Engaging means 12e are formed on the outer surface of the pipette portion Md and preferably comprise a raised portion to engage the groove 10e in the bulb. The groove ltle and base portion 12e are both formed intermediate the thickened portions 10c andfiZd whereby there will be rigid portions both on the bulb and pipette above and below the locking ring arrangement. This avoids separation of the bulb and pipette from one another under uneven stresses applied to the bulb or pipette.

To assemble the cap dropper assembly, the upper greater diameter portion of the pipette is lirst forced upwardly into the open'iower end of the bulb. Exertion of force is required as the outer diameter of the pipette upper end is greater than the inner diameter of the bulb lower end. The matching tapers of the two parts aid in the process. When the engaging ridge 12e fits into bulb groove ltle, the two pieces are locked in position relative one another. The assembled bulb :and pipette may then be positioned within the cap top by driving the bulb closed end 10a upwardly through the cap top opening 11a. As the increased diameter portion 10c of the bulb reaches the lower edge of the opening 11:1, force must be exerted to drive this portion into the opening. The tapering of the upper edge of )lilcV helps. The portion 16C and the upper end of the pipette are under compression as the flange 10d comes to rest inthe ange recess 11e.l

As an alternative method of assembling the cap dropper assembly, the bulb is pushed upwardly with its closed end 10a past the threads 11d of the cap and out through the opening 11a. When the increased outer diameter portion 10c of the bulb reaches the lower edge of the opening 11a, force must be exerted to drive this portion into the opening and the tapering of the upper portion of 10c aids in this. The portion 10c is compressed as the ilange 10d comes to rest within the flange recess 11e. The pipette is then inserted upwardly past the threads 11d of the cap so the top of the thickened portion 12d passes into the open end 10d of the bulb. The rounded upperv edge of the 12d portion of the pipette aids in this insertion but compression takes place on the pipette before it can above the upper surface of the flange recess so that the ring 12e seats above the cap top surface whereby to offer greater resistance against downward pull out of the pipette. The length of the pipette end portion 12d below the ring is essentially equal to the length of the bulb below the groove'le.

It will be observed that the top edge of the bottle will only Contact the bulb which is also the only member in Contact with the top and, thus,` if the bulb turns relative the top, which is unlikely, the pipette will turn with it as a unit and no opposing forces will be exerted on the two members. The action of the bottle top against the ange 10d of the bulb is to force it up against the under surface of the flange recess and further seal the cap.

Thus, force would have to be o bulb with the flange recess.

Thus it is seen that a complete sealing fit between the cap top and the members is afforded by the compression of the bulb within the cap top opening 11a, the extrusion of the bulb thickest portion over the top surface of the cap, and the abutment of the flange 10d of the In addition, the pipette thickened portion 12d further enforces this sealing action with the locking ring 12e sealing the pipette to the bulb and, additionally, further preventing pull out of the bulb from the cap top.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility land may be employed without reference to other features and subcombinations. Thisk is contemplated by and is Within the scope of the claims.

As many possible embodiments may be made Vof the invention without departing from the scope thereof, it is to be understood that'all matter hereinabove set forth or shown in the accompanying drawings is to be interpreted as illustrative and` not in a limiting sense.

Having thus described my invention, I claim:

1. A cap dropper assembly comprising a cap having a hole in the top thereof and a depending circumferential container engaging rim, a squeeze bulb having a closed upper end and an Open lower end, the lower end of the bulb thickened in cross section to increase its rigidity, the bulb so formedthat the outer diameter thereof above the thickened portion is not greater than the inner diameter of the cap top hole while the outer diameter of 'the thickened portion is greater than the inner diameter of the cap top hole, a radial tiange on the outer surface ofl the bulb adjacent the lower end thereof, the outer diameter of the flange being greaterrthan the inner diameter of the cap top hole, engaging means formed lin the inner surface of the bulb thickened portion intermediate the upper and lower portions thereof, a pipette having a lower discharge end and an upper engaging end, the upper engaging end wall enlarged to a greater cross-sectional thickness than the wall therebelow to increase its rigidity, the pipette upper engaging end wall also so sized as to be compressed when received in engaging relationship within the bulb lower end thickened portion when the latter is received in the cap top hole, and engaging means formed on the outer surface of the thickened portion of the pipette to mate with the engaging means on the inner surface of the bulb.

2. A cap dropper assembly as in claim 1 wherein the thickness of the cap top is less than the height of the bulb thickened portion above the bulb ange.

3. A cap dropper assembly as in claim 1 including a recess on the inside surface of the top of the cap circumferential to the hole therein whereby to receive the bulb ange.

4. A cap dropper assembly as in claim 3 wherein the recess is substantially the same diameter as the bulb ange.

5. A cap dropper assembly as in claim 3 wherein the recess is substantially the depth of the thickness of the bulb ange.

6. A cap dropper assembly as in claim 2 wherein the portion of the bulb of greater thickness which extends above the cap top upper surface when the bulb is received in the cap as a portion thereof of yet greater thickness whereby to tend to lock the bulb in the cap top when received therein.

References Cited in the le of this patent UNITED STATES PATENTS '2,772,704 McConnell et a1. Dec. 4, 1956 2,800,253 Henderson July 23, 1957 FOREIGN PATENTS 395,263 Great Britain July 13, 1933 731,069 France May 24, 1932 804,433 France Aug. 3, 1936 

